tauwetter

Tauwetter, literally thaw weather, is a period during which snow and ice melt due to rising temperatures, typically occurring in late winter or early spring in temperate regions. In meteorology the term denotes the transition from a freezing to a more temperate regime, often accompanied by increasing solar radiation and longer daylight hours. The onset can be gradual or abrupt, sometimes following a cold spell when daytime temperatures rise above freezing for several days.

During tauwetter, surface layers of snow and ice melt first, while deeper ground may still be frozen; a thaw front can move downward as soils warm. The resulting meltwater increases soil moisture and surface runoff, which can lead to mud, soggy grounds and flooding in rivers and low-lying areas, as well as potential erosion and landslides in vulnerable slopes.

Impacts on transport and infrastructure can be significant. Road and rail surfaces may become slippery or flooded, and waterlogged fields can delay agricultural activities. In mountainous regions, rapid snowmelt can produce glacial or snowmelt floods, especially when heavy rainfall accompanies thaw.

Frequency and variability: Tauwetter tends to occur annually in temperate climates, with timing depending on weather patterns; climate change may alter its onset and intensity, potentially increasing the risk of extreme melt events and rapid runoff. Historically tauwetter has been recognized in many European languages as a natural spring phenomenon.